Fast fourier transform apparatus

A fast fourier transforming apparatus performing a butterfly operation comprising:

• a radix-4 operator;
• a radix-2 operator;
• and
• operation processing means for classifying to-be-processed data that is stored in a memory into unit processing groups by grouping 2 digits starting from a LSB and determining an order of the processing groups, the operation processing means further processes a processing group of 2 digits with the radix-4 operator in accordance with the determined order for the processing groups and processes a processing group of 1 digit in last order with the radix-2 operator, and reverses the digits according to the operation processing order to recover an arrangement of total data processed by the radix operators.

A fast fourier transform apparatus for performing a butterfly operation, comprising:

• a plurality of radix operators having different bit processing rates per unit;
• a memory;
• an FFT controller having an input that receives to-be-processed data, the FFT controller being adapted to classify the to-be-processed data into data processing groups and output processing attribute information;
• a butterfly operation address generator that is connected to the FFT controller and receives the process attribute information corresponding to the data processing groups, the butterfly operation address generator being adapted to generate an operation address for the to-be-processed data in accordance with the process attribute information;
• a reverse digit address generator that is connected to the FFT controller and generates a reversed digit address to recover an arrangement of the data processed by the radix operators according to the processing attribute information;
• a first switching portion adapted to select the butterfly operation address generator or the reversed digit address generator according to a first switching control signal, and provide an output to the memory;
• and
• a second switching portion adapted to selectively connect the memory to one of the radix operators according to a second switching control signal,
• wherein the FFT controller is adapted to recover the data arrangement and output the first switching control signal and the second switching control signal according to the processing attribute information.